Basic ideas about atoms (Part 1) Flashcards
1
Q
-
3 types of radiation
A
- Alpha
- Beta
- Gamma
2
Q
What is radioactivity
A
- caused by the imbalance in the ratio of neutrons and protons
- A spontaneous emission of energy from the nucleus of a radioactive atom
- Random Process
3
Q
Alpha radiation
A
- helium atom
- Very high ionisation energy, ionises the first thing it comes into contact with
- Stopped by a sheet of paper (low penetration power)
- Has a 2+ charge but a relative atomic mass of 4 so weakly deflected towards -ve
4
Q
Beta radiation
A
- high energy electron
- Medium/ moderate ionisation power
- Penetration power= few mm of aluminium
- Has a -1 charge and small mass so strongly deflected towards +ve
5
Q
Gamma radiation
A
- Low ionisation energy (passe through)
- Stpped by lead lined concrete
- No Mass , no charge therefore not deflected
6
Q
Electron decay / inverse beta decay
A
- ## an orbital electron is captured by a proton forming a neautron and giving out an electron neutron (Ve)
7
Q
Background radiation
A
- radiation all around us due to natural and artificial sources
8
Q
Half life
A
- the time taken for half of the atoms in a radioisotope to decay
9
Q
Relative mass and charge of a proton?
A
Mass= 1
Charge = +1
10
Q
Relative mass and charge of a neutron
A
Mass = 1
Charge = 0
11
Q
Relative mass and charge of an electron?
A
Relative charge = -1
12
Q
Positron emission
A
A Proton in the nucleus changes into a neutron and a positively charged positron is emitted. The atomic number of the original element decreases by one, forming a different element
13
Q
What are the Effects of ionising radiation?
A
- damage the DNA of a cell and change how the cell functions
- overtime this can cause a mutation and the formation of cancerous cells
14
Q
Beneficial uses of radioactivity
A
- Medical Tracer
- Treatment of Cancer
- Estimating geological age of rocks
